1 #include <sys/types.h>
2 #include <sys/socket.h>
3 #include <sys/stat.h>
4 #include <sys/un.h>
5 #include <sys/wait.h>
6
7 #include <err.h>
8 #include <stdint.h>
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <unistd.h>
13
14 #define TEST_FILENAME "/tmp/passdesc"
15
16 static int test_buflen;
17 static void *test_buf;
18
19 static void
test_send_desc(int s,int fd)20 test_send_desc(int s, int fd)
21 {
22 struct msghdr msg;
23 struct iovec iov;
24 union {
25 struct cmsghdr cm;
26 uint8_t data[CMSG_SPACE(sizeof(int))];
27 } ctrl;
28 struct cmsghdr *cm;
29 int n;
30
31 iov.iov_base = test_buf;
32 iov.iov_len = test_buflen;
33
34 memset(&msg, 0, sizeof(msg));
35 msg.msg_iov = &iov;
36 msg.msg_iovlen = 1;
37 msg.msg_control = ctrl.data;
38 msg.msg_controllen = sizeof(ctrl.data);
39
40 memset(&ctrl, 0, sizeof(ctrl));
41 cm = CMSG_FIRSTHDR(&msg);
42 cm->cmsg_len = CMSG_LEN(sizeof(int));
43 cm->cmsg_level = SOL_SOCKET;
44 cm->cmsg_type = SCM_RIGHTS;
45 *((int *)CMSG_DATA(cm)) = fd;
46
47 n = sendmsg(s, &msg, 0);
48 if (n < 0)
49 err(1, "sendmsg failed");
50 else if (n != test_buflen)
51 errx(1, "sendmsg sent %d", n);
52 close(fd);
53 }
54
55 static void
test_recv_desc(int s)56 test_recv_desc(int s)
57 {
58 struct msghdr msg;
59 struct iovec iov;
60 union {
61 struct cmsghdr cm;
62 uint8_t data[CMSG_SPACE(sizeof(int))];
63 } ctrl;
64 struct cmsghdr *cm;
65 int n, fd;
66 char data[16];
67
68 iov.iov_base = test_buf;
69 iov.iov_len = test_buflen;
70
71 memset(&msg, 0, sizeof(msg));
72 msg.msg_iov = &iov;
73 msg.msg_iovlen = 1;
74 msg.msg_control = ctrl.data;
75 msg.msg_controllen = sizeof(ctrl.data);
76
77 n = recvmsg(s, &msg, MSG_WAITALL);
78 if (n < 0)
79 err(1, "recvmsg failed");
80 else if (n != test_buflen)
81 errx(1, "recvmsg received %d", n);
82
83 cm = CMSG_FIRSTHDR(&msg);
84 if (cm == NULL)
85 errx(1, "no cmsg");
86 if (cm->cmsg_len != CMSG_LEN(sizeof(int)))
87 errx(1, "cmsg len mismatch");
88 if (cm->cmsg_level != SOL_SOCKET)
89 errx(1, "cmsg level mismatch");
90 if (cm->cmsg_type != SCM_RIGHTS)
91 errx(1, "cmsg type mismatch");
92
93 fd = *((int *)CMSG_DATA(cm));
94
95 n = read(fd, data, sizeof(data) - 1);
96 if (n < 0)
97 err(1, "read failed");
98 data[n] = '\0';
99
100 fprintf(stderr, "fd content: %s\n", data);
101 }
102
103 static void
usage(const char * cmd)104 usage(const char *cmd)
105 {
106 fprintf(stderr, "%s [-d] [-s] [-p payload_len]\n", cmd);
107 exit(1);
108 }
109
110 int
main(int argc,char * argv[])111 main(int argc, char *argv[])
112 {
113 int s[2], fd, status, n, discard, skipfd;
114 int opt;
115 off_t ofs;
116
117 discard = 0;
118 skipfd = 0;
119 while ((opt = getopt(argc, argv, "dp:s")) != -1) {
120 switch (opt) {
121 case 'd':
122 discard = 1;
123 break;
124
125 case 'p':
126 test_buflen = strtoul(optarg, NULL, 10);
127 break;
128
129 case 's':
130 skipfd = 1;
131 break;
132
133 default:
134 usage(argv[0]);
135 }
136 }
137
138 if (test_buflen <= 0)
139 test_buflen = sizeof(int);
140 test_buf = malloc(test_buflen);
141 if (test_buf == NULL)
142 err(1, "malloc %d failed", test_buflen);
143
144 if (socketpair(AF_LOCAL, SOCK_STREAM, 0, s) < 0)
145 err(1, "socketpair(LOCAL, STREAM) failed");
146
147 if (fork() == 0) {
148 close(s[0]);
149 if (!discard && !skipfd) {
150 test_recv_desc(s[1]);
151 } else if (skipfd) {
152 int buf;
153
154 fprintf(stderr, "skipfd\n");
155 n = read(s[1], &buf, sizeof(buf));
156 if (n < 0)
157 err(1, "read failed");
158 } else {
159 fprintf(stderr, "discard msg\n");
160 sleep(5);
161 }
162 exit(0);
163 }
164 close(s[1]);
165
166 fd = open(TEST_FILENAME, O_RDWR | O_TRUNC | O_CREAT,
167 S_IWUSR | S_IRUSR | S_IRGRP | S_IROTH);
168 if (fd < 0)
169 err(1, "open " TEST_FILENAME " failed");
170
171 n = write(fd, TEST_FILENAME, strlen(TEST_FILENAME));
172 if (n < 0)
173 err(1, "write failed");
174 else if (n != strlen(TEST_FILENAME))
175 errx(1, "write %d", n);
176
177 ofs = lseek(fd, 0, SEEK_SET);
178 if (ofs < 0)
179 err(1, "lseek failed");
180 else if (ofs != 0)
181 errx(1, "lseek offset %jd", (intmax_t)ofs);
182
183 test_send_desc(s[0], fd);
184
185 wait(&status);
186 exit(0);
187 }
188